The objective of this research is to correlate breast tissue, serum, and urine lactic dehydrogenase (LDH) and malic dehydrogenase (MDH) isoenzyme alterations from pat with breat tissue pathology, i.e., fibroadenoma, fibrocystic disease, and carcinoma. Examination of this data will determine if a highly reproducible test can be developed for the enzymatic detection of breast carcinoma. In addition, alterations in serum, urine, and tissue isoenzymes may be of a prognostic value and aid in staging of the disease at the time of surgery. Additional studies will be done to follow the course of the disease by serum and tissue isoenzyme assay after treatment to determine if recurrent disease at a later date will again cause atypia in isoenzyme patterns.